Magnetic pickup tool

ABSTRACT

A magnetic pickup tool including a length of highly flexible tubing with a permanent magnet secured to one end of the tubing. Removably positioned within the interior of the flexible tube is a [stiffening means] stiffener such as a length of iron wire of about the same length as the flexible tubing. The [stiffening means] stiffener is bendable but when bent has the ability to take a &#34;set&#34;. A second length of flexible tubing completely surrounds the first or inner tubing and is slidable thereon. The function of the outer tube is to surround the magnetic tip when the tool is in the process of being positioned to pick up an object so as to prevent the magnetic tip of the tool from being attracted to an unwanted metal object. After the tool has been positioned at or near the object to be picked up, the user then grasps the outer tube and pulls it away from the magnetic tip exposing the tip to make contact with the desired object. A feature of the tool is that the [stiffening means] stiffener is removable. Thus, where the tool is being used to retrieve an object which requires that the tool have a very high degree of flexibility, the [stiffening means] stiffener is removed and then the entire length of the tool can be bent in virtually any type of configuration. Further features include a magnetic tip insulated from the rest of the tool to prevent electrical shock to the user, and a dome-shaped end of the tool to reduce the tendency of the tool getting caught on other objects when used.

This application is a continuation-in-part of application Ser. No.07/804,813 filed Dec. 9, 1991, now U.S. Pat. No. 5,169,193.

FIELD OF THE INVENTION

The present invention relates to a magnetic pickup or retrieval tool forretrieving magnetically attractable objects such as screws, bolts andthe like from highly inaccessible places.

BACKGROUND OF THE INVENTION

A rather wide variety of magnetic pickup tools for retrievingmagnetically attractable objects are known which include a somewhatflexible shaft for manipulating a magnet on the end of the shaft into anotherwise inaccessible area. Such tools are often employed in tightplaces surrounded by metal parts which of course are also magneticallyattractable. Therefore, it is often difficult to control the positioningof the magnet on the tool in such situations and particularly so sincethe flexible shaft causes the magnet to be drawn toward such metalparts.

Various magnetic devices are known for varying the strength of a magnetand include compound magnet systems where the relative orientation oftwo or more magnets is adjusted to adjust the magnetic force.Additionally, magnetic tools are known where the distance between themagnet and the working face is adjusted to decrease the magnetic forceapplied at the face. However, these types of devices often do notprovide sufficient magnetic force and do not substantially decrease thelateral magnetic attraction toward surrounding magnetically attractablematerials. U.S. Pat. No. 4,813,729 discloses a magnetic retrieval toolwhich is said to overcome the foregoing problems. Additionally, U.S.Pat. No. 512,381 shows a magnetic pickup tool in which the magnet isslidably located in an outer sleeve. Although the tool of this patentdoes overcome the problem of the magnet being attracted to otherunwanted magnetic articles, the shaft of this tool is not flexible andthus severely limits the use of the tool. A somewhat similar arrangementis shown in U.S. Pat. No. 2,471,764 and it appears that the tool of thispatent is also subject to the problem of the shaft being totallyinflexible. In U.S. Pat. No. 2,683,618 there is also shown an automaticpickup device which provides for shielding of the magnet and alsoincorporates a somewhat flexible shaft. Interestingly, the tools ofthese patents are quite complicated in construction and obviously rathercostly to make.

Accordingly, it is a principal object of this invention to provide amagnetic pickup tool in which the flexibility of the shaft can be widelyvaried and in which the magnet which is employed may be moved from aninoperative to an operative position in order to prevent the magnet frombeing attracted to unwanted metal objects during positioning of thetool. A further object of this invention is to provide a magnetic pickuptool which is simple in construction and of very low cost. These andother objects of the invention will become more apparent as thisspecification proceeds.

SUMMARY OF THE INVENTION

In accordance with one form of the invention, a magnetic pickup tool isprovided which includes a length of highly flexible tubing with apermanent magnet secured to one end of the tubing. Removably positionedwithin the interior of this highly flexible tube is a stiffening meanssuch as a length of iron wire which is of about the same length as theflexible tubing, the stiffening means being bendable but when bent thestiffening means takes a "set". A second length of flexible tubingcompletely surrounds the first or inner tubing and is slidable thereon.The function of the outer tube is to surround the magnetic tip when thetool is in the process of being positioned to pick up an object so as toprevent the magnetic tip of the tool from being attracted to an unwantedmetal object. After the tool has been positioned at or near the objectto be picked up, the user then grasps the outer tube and pulls it awayfrom the magnetic tip exposing the tip to make contact with the desiredobject. A further feature of the tool is that the stiffening means isremovable. Thus, where the tool is being used to retrieve an objectwhich requires that the tool have a very high degree of flexibility, thestiffening means is removed and then the entire length of the tool canbe bent in virtually any type of configuration.

In a most preferred embodiment the end of the magnetic pickup toolsurrounding the permanent magnet is dome or hemispherical shaped toreduce the tendency of the tool getting caught on other objects when itis being used. Additionally, the magnetic tip of the tool is insulatedfrom the rest of the tool in such a manner that when the magnetic tiptouches an exposed electrical connection carrying a current, themagnetic tip, which is usually metal, will not conduct the current tothe user.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view of a preferred embodiment of the tool ofthe present invention which is shown in partial cross-section;

FIG. 2 is an enlarged partially cross-sectional view of the tool of FIG.1;

FIG. 3 is a partial view in partial cross-section showing the tool beingplaced near a metal object such as an engine block;

FIG. 4 is a partial view in partial cross-section showing the toolpicking up a nut near an engine block;

FIG. 5 is a partial view in partial cross-section showing release of thenut from the magnetic tip of the tool;

FIG. 6 are perspective views of the basic components of the tool of thepresent invention;

FIG. 7 is an elevational view of a further embodiment of the tool of thepresent invention which is shown in partial cross-section;

FIG. 8 is an enlarged partially cross-sectional view of the areadesignated "8" of FIG. 7; and

FIG. 9 is a longitudinal partially sectional and partially perspectiveview of the tool of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings in which like reference numerals designatelike or corresponding parts throughout the various views, there is shownin FIGS. 1 and 2 a magnetic pickup tool 10 in accordance with thepresent invention. Tool 10 includes a length of a first highly flexibletube 15 with a permanent magnet 16 secured to one end of tube 15. Asshown, a portion of magnet 16 is inserted into one end of tube 15 andcan be secured in a permanent fashion by means of a suitable adhesive.Tube 15 can be formed of, for example, an elastomer such as natural orsynthetic rubber or a synthetic plastic such as polyvinylchloride (PVC).A PVC tube being brightly colored to promote visability is preferred.

Positioned within tube 15 is removable stiffening means 25 which is ofsmaller diameter than the inside diameter of tube 15 so that it isreadily inserted and removed and which, as shown, is a length of metalwire such as iron, copper or brass and of substantially the same lengthas tube 15. It is important that wire 25 be such that it is flexible orbendable but also must be able to take a "set" as shown in FIG. 6. Thatis, when the wire is bent to a certain shape, it will retain that shapeuntil the shape is deliberately changed. Also, as shown in FIGS. 1 and2, one end of the wire is provided with a cap 26, a portion of whichfits snugly into the interior of the tube 15. The cap makes it easy toremove the wire from the tube and then reinsert it.

A second outer tube 20 surrounds the first tube 15 and is slidablethereon. Tube 20 is made of the same or similar material as tube 15 andagain is highly flexible as is tube 15. The purpose of tube 20 is tosurround the magnetic tip when the tool is in the process of beingpositioned to pick up an object. For example, as shown in FIG. 3, whenthe tool 10 is in the process of being positioned to pick up an object,and in this instance an object which is near metal engine block 18, theouter tube 20 shields the magnet and prevents it from being attracted toengine block 18. Then, as shown in FIG. 4, when the end of the tool isnear the object to be retrieved, in this instance nut 22, the usergrasps outer tube 20 and pulls it away from the magnetic tip exposingthe tip to make contact with nut 22. This can be done with one hand.Thereafter, as shown in FIG. 5, once the object has been retrieved andbrought to a suitable location, the outer tube can then be moved so thatit again surrounds the magnetic tip 16 and the tool is ready foradditional use. To enhance the slideability of outer tube 20 withrespect to tube 15, it is recommended that a small amount of a drylubricant such as powdered graphite, talcum powder and the like beapplied to the outer surface of tube 15.

The tool shown in FIGS. 7-9 incorporates several improvements over thetool previously shown and described. As shown in FIGS. 7-9, the end ofthe magnetic pickup tool surrounding the permanent magnet is generallydome or hemispherical shaped to reduce the tendency of the tool gettingcaught on other objects when in use. Specifically, insert 30 having arounded exterior surface 32 and passageway 31 is placed into the end ofouter tube 20. Passageway 31 is provided to allow exposure of magnet 35.Additionally, in the tool shown in FIGS. 7-9, the magnetic tip 31 isinsulated from the stiffening means 25 by means of rod 33 which is madefrom an electrically non-conductive material. As shown, permanent magnet35 is secured to one end of rod 33. The other end of rod 33 is insertedin the end of first tube 15 and can be secured to tube 15 in a permanentfashion by means of a suitable adhesive. Thus, where stiffening means 25is a metal wire for example, rod 33 completely insulates the user'shands from possible electrical shock when the magnetic tip 35 makescontact with a current carrying electrical contact.

The pickup tool of this invention is highly adaptable to retrievingmetal objects in a wide variety of situations. For example, when thewire 25 is in place in the tool, the tool can be bent into a complexshape such as for example that shown in FIG. 6 and it will retain thatshape until the object has been retrieved, at which time the tool canthen be straightened and ready to use again. However, there may well beother situations where a very high degree of flexibility of theretrieval tool is required. In such a situation, the stiffening means,wire 25, can be completely removed from the tool and then the magneticpickup tool, because of the very high degree of flexibility of tubes 15and 20 will be able to follow almost any course to retrieve the desiredobject.

I claim:
 1. A magnetic pickup tool comprising a first length of aflexible tube with a permanent magnet secured to one end thereof,removable stiffening means positioned within said first tube, saidstiffening means being of smaller diameter than the inside diameter ofsaid tube and of substantially the same length thereof, a secondflexible tube surrounding said first tube and slideable thereon wherebysaid second tube may be moved in a direction to fully surround saidmagnet and in an opposite direction to expose said magnet, saidstiffening means being bendable into a variety of shapes and when bentto a desired shape will retain said shape until deliberately changed,with the end of said second tube which surrounds the magnet being domeshaped.
 2. The tool of claim 1 wherein said stiffening means is a metalwire, wherein said tubes are formed of an elastomer and wherein saidmagnet is separated from said wire by means of an electricallynon-conductive rod.
 3. The tool of claim 2 wherein said stiffening meansis iron wire and said tubes are made of polyvinylchloride.